Condenser



N811. 17, 1931. s, l, COLE 1,812,098

CONDENS ER Filed April 2, 1925 t 30 folded over foil sheets.

Patented Nov. 17, 1931 hill UNITED a oonronafrron or anw venir @@NFDEN pplication tiled April El, 19%. serial lilo. 26,683..

The invention relates-more especially to condensers of small and 'fixed capacity for radio use, although the invention is not limited to such application.

- lt is among the objects of the invention to provide a condenser of the type mentioned which shall be easy to manufacture, ol rugged construction, the capacity of which is substantially invariant in all conditions oi handling and use, which shall 4be susceptible ol being v readily mounted without the need for tools other than a'screw driver, which shall not be dependent for operat-iveness o n exerting Aa clamping pressure on the pack, and which shall be substantially prooi` against tampering. A

I preferably employ a condenser pack which is preformed under pressure and heat so that the laminated foil sheets of the pack take a rm set and the dielectric laminations of the pack become adherently fastened together, as described and claimed in the copending application of Samuel Siegel, Serial No. 750,966 filed November 20, 1924., n My invention is concerned more especially with protective and terminal structures lor the pack, I fold the foil sheets about tlie ends of insulating backing sheets and provide metallic terminal plates in contact with said Terminal posts entend through the pack and the terminal plates maintaining said parts assembled, 4without however, aecting the capacity of the preformed stack. ln the preferred embodiment, the terminal plates are bowed, so that in tightening the posts in position, the bowed 'sheets will become attened and exert pressures piimarily at the edges ot the backing sheets-to prevent the same from curlingor warping', the posts being `preferably constructed and arranged to avoid any substantial pressure on the preformed stack.

To avoid rockin of the plates about the terminal posts, said plates are preferably provided with lateral ears overlapping the edges-of the backing plates. For mounting a grid leak, l employ auxiliary supporting anglebrackets therefor which may be secured in place by the terminal posts, and having a lateral edge maintained against rocking by vengagement with the slightly protruding stood :trein the following description in conf i nection with the accompanying drawings wherein:

Figure l is a perspective view oi a condenser embodying the invention,

Figure 2 is an similar view with the reverse side or the condenser exposed, A l

Figure 3 is an enlarged transverse section on the line 3-3 of Figure l,

Figure 4; is a disassembled perspective view of the two securing plates,

Figures 5 and 6 are sectionalviews on the line 6--6 of Figure 2, Figure 5\V indicating the position of the parts before a riveting operation and Figure 6 indicating the position of the parts after a riveting operation,

Figure 7 is a perspective view of a modiiied torni of condenser,

Figure 8 is a view similar to Figure l showing the reverseside ot the condenser, and

Figure 9 is perspective view of one oil the securing plates.

The individual elements ot the pack, as well as the backing sheets may be of familiar construction including toil sheets ll interleaved vvitlr thin sheets l2 preferably of mica or similar thin denible dielectric material with 'the ends of alternate toil sheets projecting beyond oppositeedges of the pack and iiolded over the edge ot one oi the backing sheets l0 as indicated at i3, (Figure 3) rilhus the ends of all the toil sheets havinglike polarityniay be electrically connected together by the use ot suitable terminal. posts ll which may serve both as supports and as convenient points attachment tor electrical conductors.,

Preferably, as set forth and claimed in the copending application above referred to, the various 'foil sheets and dielectric sheets are impregnated with parailine and subjected to pressure and heat, as by heated plates or rollers. Fiacess parane is thereby squeezed out, and the parts take a Frm-set and become adherently connected together. l,

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rlhe stack is protected according to my invention, and adapted for ready mounting by placing it between two plates of bakelite or similar insulating material. .The alternate foil sheets are bent over the outside of the backing sheets and terminal contact is established by means of angle-shaped terminal plates 15, which are superposed over one of the backing plates and have upstanding edges protruding beyond the other backing plate, there being a complementary generally flat metal plate 16 superposed over the other backing plate. In the preferred embodiment the superposed plates 16 and, if desired, also the angle plates are initially bowed as best shown in Figure 5, and the assembly is completed by means of headed terminal posts 19v contacting the angle plate as at 21 having hollow shanks extending through corresponding apertures in the stack and turned or rolled over at their ends as at 23, by that operation flattening the curved plate 16 as best shown in Figures 6. The rolling over tool is preferably so constructed that in the process of operation, the extent of depression is limited so that the curved plate will only be approximately flattened without exerting any additional direct downward pressure vupon the stack. As a consequence while the terminal post serves to effect a suiiicient electrical contact between the plate 15 and the turned-over ends of the foil, yet no material direct pressure is thereby exerted upon the stack, and, as tests have repeatedly shown, the

capacity of the stack after it has been as-A sembled, is precisely the same as it was when the stack itself was completed and before applying 'the backing sheets, the terminal plates and the assembling posts.

' Another feature ofl importance is the provision of tongues 25, 26 at the edges of the arm 17 of securing plate 15 at the ends of plate 16, said tongues embracing the lateral edges of the stiff backing sheets and positively preventing rocking displacement of either of the securing pla-tes about the securing devices 14 as centers. By preventing such displacement, I eliminate the possibility of altering, injuring, or losing the electrical contact between the terminal ends of the folded foil sheets and the terminal plates, which might otherwise be incurred in the ordinary course of packing, transportation, installation or use. It will be noted that the edge of the angle plate protrudes beyond the companion plate 16r so as to render'possible the use of the 15 by the same binding post attaching means l 23 which secured the stack, the backing plates and the terminal plates in assembled relation. Inasmuch as the length of the grid leak resistance may be greater than that of the condenser the upstanding arms of the bracket protrude beyond the/ condenser and an angle-shaped dent 41 is formed at the angle of the bracket, the upstanding part 42 of said dent contacting the upstanding edge of the terminal plate. By this arrangement as will be readily seen, the terminalbrackets bowed to prevent undue pressure and warp-v ing of the latter, when the post ends are turned over. In this case, the heads 21 of the This relation of parts moreover,

securing devices hold one of the backingi sheets and the turned over ends 23 of the tubular sections 20 of the securing devices hold the securing plates, and also preferably clamp terminals 32 to the securing plates. 'Ihese terminals are of usual type, suitable for soldering attachment to electrical conductors forming lthe condenser leads, and may, of course, also be used' in the embodiment of Figures 1 to 6.

The tapped` posts in both embodiments may be used as electrical binding posts or as mountin posts or for both purposes concurrently. or each use, a screw need merely be threaded thereinto, without the need for a nut, which would be necessary were the post or other fastening element merely perforated and not tapped.

In connection with the foregoing description, it will be noted that in every case, I preform and press the condenserpack and assemble it as a unit and thus guard against the necessity for exerting pressure on the pack i during assembly, which might produce undesirable changes in capacity or by varying the compression on a portion or portions of the pack. In every case, I have guarded against any slippage of the terminal clips which might result in a faulty electrical connection between the clips and the ends of the foil sheets. In every case, also, I safeguard against warping ofthe backing sheets and provide for the ready attachment of electrical conductors. Means are provided for both-supporting the condensers and attaching lead Wires, slnce the securing devices may be optionally used either as supports or rocking about the cylindrical fastening memterminals.

Having thus described my invention, what er. Signed at New York, in the county of I claim as new and desire to secure by Let- New York andState of New York, this 30th ters Patent is 1. A condenser including backing sheets of relatively stiff insulating material, a condenser pack between the sheets, pairs of cooperating securing plates disposed on opposite sides of the sheets, and held against relative separation by securing devices passing through the plates, sheets and pack, said securing devices each having one end upset over one of the securing plates and their otherends headed, and internally threaded to receive a supporting screw.

2. A condenser comprising in combination, a condenser stack, angle shaped terminal plates super-posed over one side of the stack and having their edges in contact with the ends of the stack, and protruding therebeyond, upstanding terminal brackets superposed over the stack on the side opposite said terminal plates and having a portion extending lengthwise of said protruding edge., cylindrical fastening members penetrating said stack, said terminal plate and said bracket, said terminal plate having lateral tongues embracing the stack whereby the various parts will be maintained against rocking displacement about said cylindrical fastening element.

3. A condenser comprising a stack of alternating, conducting and insulating sheets, insulating backing sheets for said stack, angle-shaped terminal plates, and having an arm superposed over one of said backing plates, and the other arm extending across the Iend of the stack, and protruding therebeyond, terminal brackets for a grid leak resistance of greater length than said condenser, said l brackets being angle-shaped and including a dented portion extending the width of and contacting with the protruding terminal plate portion, and cylindrical fastening members penetrating the stack, the bracket and the terminal portions.

4. A condenser comprising a stack ot alsternating, conducting and insulating sheets,

insulating backing sheets for said stack, angle shaped terminal plates, and `having an arm superposed over one of said backing plates, and the other arm extending across the end of the stack, and protruding therebeyond, terminal brackets for a grid leak resistance of greater length than said condenser, said brackets being angle `shaped and including a dented portion extending the width of the protruding terminal plate portion, cylindrical fastening members penetrating the stack. the bracket, and the terminal portions, and lugs on said terminal plate embracing the edges of the backing plates, whereby the various parts will be retained against day of March, A. l). 1925.

SAMUEL I. COLE.

CMD 

